Screened coils provided with a device for adjusting the selfinductance



Aug. 14, 1934.V H.v RlNlA SCREENED CO'ILS PROVIDED WITH A DEVICE FOR ADJUSTIG THE SELF INDUCTACE Filed oct. 15, 1950 fige- Q21 INVENTOR HERRE Rmm ATTORNEY 5 metal mass may be constituted.

D consists or insulating Patented Aug. I4, -1934 UNITED STATES PATENT OFFICE Een Peeuemw'm mnUoTANoE Herre Rinla, Eindhoven, Netherlands, lsslmor to Radio Corporation of America, a oorpoiation of Ware Application October l5, 1930. Serial No. In the Netherlands 488,755 October 25, 1929 1 Claim.` (C1. P11-119i In the series-manufacture of screened coils,

mutually diierent self-inductances.

densers with a single device.

These diiliculties are particularly prevalent it it is desired to provide in the screening case a. plurality of coils destined for diierent ranges of wave-lengths.

The for example by a When cylindrical coils even4 may be advantageous in disc or a closed winding It a plurality oi coils are n'anged within the case, each coil is provided with a separate rotatable metal disc mass. The above mentioned arrangement at the end of the coils affords the endsoftheeolu or otherwise shapedY special advantage that;A being the selt-,inductances of the various combinations can be adjusted without an adjustment beingLa inuenced by the following adjustment..

The I'lrs The coils ot the same series consequently become substantially equal to one another so that they can be replaced at once withoutl alteration of the tuning o! the apparatus.,

Theendotthe two ends of the coil Iheooil4isc0nnectedtooneottheendof the coil 5 whose other end is led out'I of the case, Four wires in total consequently emerge from eSil vil@

may be nxed by soldering. Inthls case care should be taken that there remain no gaps between the ends of the spindles and the wall, owing to which the magnetic field might emerge from the case.

It is obvious that various changes and modifications may be made to the details ot construction of the invention given above without departing from the general spirit oi the invention.

The adjustment o! the self-inductance preferably` occurs in such manner that rst the inductance oi the coil 3 is adjusted by tuning the spindle 17 while short-circuiting the coils 4 and 5. Subsequently the coils 3 and 4 are connected in series, the coil 5 being short-circulted. The disc 12 is turned until the total inductance of the coils 3 and 4 has the desired value.

The alteration of the position oi the disc 12 has no influence on the inductance of the coil 3 for 12 is arranged in such manner that the coil 4 acts as a screen between the disc 12 and the coil 3. In a similar manner the coil 5 acts as a screen for the disc 13 so that the latter can be turned without any influence being exerted on the coil 4.

It has been found that in the manner above described a very rapid and exact adjustment of the inductance is possible without alteration oi the capacity of the coils. Particularly for the series-manufacture of inductance coils destined for receiving sets comprising a plurality o! condensers mounted on a shaft, such an adjustment of the inductance is of very great importance.

I claim:

In a coil system ior use in tunable circuits adapted to be adjusted to diierent frequency ranges, an inductance winding comprising at least two separate coils enclosed within a shielding device, means external the shielding device to allow the connection of both -the coils in series so as to provide a different inductance value than the inductance value o! either coil, an adjustable conductive body within said shielding device and associated with one of 'said coils ior individually adjusting the inductance value thereof, said conductive body being disposed with respect to the two coils so that the coil associated with the conductive body acts as a shielding element between the conductive body and the other coil, a second adjustable conductive body within said device and associated with said other coil for adjusting the total inductance value of both coils when connected in series, said second conductive body being disposed with respect to the two coils so that the coil associated with the second conductive body acts as a shielding element between the second conductive body and the first coil.

HEERE RINIA.

IIB 

